Are we Alone In The Universe?

The cosmos confronted with huge spans of time, as well as stupendous expanses of space. Life on Earth has evolved for billions of years, but our Sun has burnt up less than half its fuel, and will keep shining for another five billion years. If life isn't prematurely snuffed out, our remote progeny will surely -- in the aeons that lie ahead -- spread far beyond this planet.

We plainly can't forecast the vastly remote future. But what might happen in the first decades of the new millennium? How long will it be before people return to the Moon, and perhaps explore still further afield?

NASA Worth its weight in gold - a section of the International Space Station

The centerpiece of the current US programme is the new International Space Station: this will be in orbit a few hundred miles up, and the size of a football field. It will be the most expensive artifact ever constructed, costing its own weight in gold. Even if it is finished -- something that seems uncertain, given the immense and ever-rising costs, and prolonged delays -- it will be neither practical nor inspiring. Thirty years after men walked on the Moon, a new generation of astronauts will be going round and round the Earth, in more comfort than Mir can offer, but much more expensively. The astronauts will be able to do experiments, but most of those could be done more cheaply by robots in smaller free-flying satellites.

The Space Station would make somewhat more sense as a staging post on the way to other planets. But no such follow-up will materialise unless public enthusiasm revives, or unless some technical breakthrough renders space travel much cheaper and easier than it now seems.

Present launching techniques are as extravagant as air travel would be if the plane had to be rebuilt after every flight. Spaceflight will only be affordable when it adopts the same techniques as supersonic aircraft. Tourist trips into orbit may then become routine. And wealthy adventurers may boldly go further. Future Richard Bransons, for whom round-the-world ballooning seems too tame and routine, could aim for the Moon. If Bill Gates seeks a challenge that won't make his later life seem an anticlimax, he could sponsor the first expedition to Mars.